Various proposals have been made in publications to use gallium arsenide as semiconductor material for charge coupled components (CCD). Due to the fact that charge carriers in gallium arsenide exhibit a higher degree of mobility and a higher diffusion coefficient in comparison to silicon, charge-coupled components of this type on gallium arsenide can be expected to display shorter charge transport times than charge-coupled elements constructed on silicon (AEU, Vol. 29, 1975, Vol. 6, page 286 to 288). It has been proposed that charge-coupled components of this type constructed as gallium arsenide CCDs should be designed not in the manner of MOS-capacitors, but that Schottky contacts be provided as electrodes (Proc. of the IEEE, November 1972, page 1444 to 1445; Proc. of the Intern. Conf. on Technology and Applications of Charge-Coupled Devices, Edinburgh September 1974, page 270 to 273). In accordance with these proposals, the principle of a peristaltic CCD is employed for components of this type (Electronic Letters 8, December 1972, Page 620 to 621) or Bulk Channel CCD (Bell System Technical Journal, September 1972, page 1635 to 1640). Here majority charge carriers, for example, electrons, are transported in an n-conducting zone. When a blocking voltage is connected between a p-conducting substrate and the n-conducting layer, a potential well in which a charge is stored is formed in the n-conducting zone. The use of a p-substrate for charge-coupled components constructed on gallium arsenide has the disadvantage, however, that the read-out and amplifier circuits required for the signal processing become relatively slow due to the parasitic capacitance of the pn-junction prevailing between the n-conducting layer and the p-conducting substrate, and that consequently the speed advantages gained on account of the higher degree of mobility of the charge carriers in the gallium arsenide, are lost.
Currently, charge-coupled elements with silicon semi-conductors operate throughout with MOS-capacitors. It has previously been impossible to successfully transfer this principle to charge-coupled elements constructed on gallium arsenide due to the fact that the boundary surface between GaAs and a dielectric arranged beneath a CCD electrode does not exhibit the requisite low energy level density. As a result, it is not possible to influence the space charge zone width in the GaAs in the desired manner or to produce inversion layers on the semiconductor surface. A further outcome of the excessively high energy level density is the frequency dependency which can be observed in MIS structures constructed on GaAs and the hysteresis of the capacitance which has a disadvantageous influence upon the operation of CCD circuits.